Method and apparatus for vulcanizing tires



Oct. 5 1926. l 1,601,955

J. R. GAMMETER METHOD AND APPARATUS FOR VULCANIZING TIRES Filed Feb. 6, 1924 2 Sheets-Sheet l Il i 15a l5 l l j um i;

1 I llnn Oct. 5 1926. 11,601,955

.1. R. GAMMETER METHOD AND APPARATUS FOR VULCANIZING TIRES Filed Feb, 6, 1924 2 Sheets-Shee 2 Patented Ot. 5, 1926.

UNITED i STATES PATENT ,'oFFicE.

JOHN R. GAMME'IER, OF AKRON, OHIO, ASSIGNOR TO` THE B. F. GOODRICH COMPANY, f

i OF NEW YORK, N. Y.,`A CORPORATION OF NEW YORK.

METHOD .AND APPARATUS FOR VULCANIZING TIRES.

Application mea February e, 1924. serial No. 690,963.

This invention relates to the art of vulcanizing rubber articles and is of especial value Vin vulcanizing hollow rubber articles such as pneumatic tire casings, where a heating'or distending fluid is conducted into the article or into a hollow clore upon which the article is vulcanized.

In procedure heretofore employed,a tire, for example, has been expanded against the mold in which it is vulcanized by forcing a pressure Huid into an expansible core within the tire, and in orderto soften the rubber of the tire before expanding it and also to rid the core of air, steam has first been injected into the core at less than expanding pressure, condensing to water at a temperature above the normal, boiling point, and after the tire has thus been heated to a softening temperature the core has been vented through its inlet tube, the condensed water thereupon flashing back into steam,

mixing with the air, and the mixture of air and steam escapingfromvthe core. Steam or water at high pressure -and temperature has then been forced into the core, distending the latter to expand the tire against the mold and to vulcanize it in its expanded condition. In such procedure, however, some time `has been required for the initial,` warming of thev tir and condensation of steam ata temperature above the normal boiling point, and the Venting of the core through the inlet tube has also delayed the operation.

A While the initial charge of steam is being condensed, different parts of the core cavity are occupied by steam, air and water o condensation, respectively, with the result that forv an appreciable time the inner sur-A face of the tire is not heated at the same rate throughout- M y invention is an improvement upon the procedure just described, my chief ob] ect being to secure an improved product, to shorten the vulcanizing operation, and" more particularly to provide a methodand apparatus whereby a hollow rubber article, such as a tire, may be'quiekly and uniformly heated from the interior, either to a vulcanizing temperature or, initially, only to a temperatiire such as to soften the rubber and permit the article to be readily and uniformly expanded against the mold4 in which it is vulcanized. Furtherobjectsareto avoid rapid deterioration of the expansible core upon which` the article may be vulcanized, and to insure uniformity of temperature in successive vulcanizing operations.

In brief my invention provides apparatus and'procedure whereby the air initially contained within the hollow article or Vulcanizing core may be` quickly eliminated by circulating a fluid, preferably steam, therethrough, the steam being admitted at one point and at the same time vented at a different point, in a manner Such that the fluid will be`required to iow throughoutsubstantially the entire space which is to be rid of air. Thus the air may be disposed of before the expansible core, for example, has been subjected to a prolonged heating, so that the destructive oxidizing effect of the. air upon the core may be minimized. A. temperature controlled relief valve is connected to the vent 'of the space within the article and is set to close automatically at a determinate temperature, which is reached after the air has been expelled, the closing of the valve permitting the article to be- `further 'heated and expanded by the conf in section, of an expansible core constituting a part of said apparatus. I

Fig. 3 is a similar view of a modied form of core. v

',Fig. 4 is a similar view of another modication of the core.

Fig. 5 is a longitudinal section of a temperature controlled relief valve usedon the v FigfG is a longitudinal section of a modition, having the usual steam and drain connections 11 and 12, interlocking cover 13 and ram 14, thelatter being adapted to support a stack of tire molds 15, 15, and press the same against the lower one of a pair of annular, pressure equalizer members 16, 16, the upper one of which abuts `the heaterpress cover. The uppermost mold ofthe stack, in Fig. 1, is shown in section, with a tire 17 and an expansible vulcanizing core 18 therein, the core being provided with a liuid inlet tube 19 and a temperature controlled relief valve 20 opposite thereto, said inlet tube 19 having connection through a fieXible pipe 21 with a sectional manifold or header, the uppermost section of which is shown at 22, various types of sectional manifolds suitable for this purpose being. well known in the art. The tire mold l5, of

the type here shown, is provided with a pair of bead clamping rings 15a, 15a, the latter being formed with suitable grooves to accommodate the inlet tube 19 and the tube upon which the relief valve 20 is mounted.

For supplying a heating or pressure fluid to said manifold, apipe structure 23 leads into the vulcanizer through a side wall thereof, and connected to said pipe structure by a telescope joint 24 is a pipe structure 25 extending upward beside the sta-ck of molds and horizontally over` the uppermost Amold to the center ofthe stack, the lowermost equalizel` member 16 'being grooved to accommodate it. 26 is a' plug and socket coupling member connecting said pipe structure 25 with the uppermost section22 of the manifold, and said couplingmember is formed with a tapered portion 27 projecting upward and receiving the apertured hub of a'spider 28 mounted upon the lower equalizer member 16, for positioning the stack of manifold sections 22, this arrangement` being such that the equalizer members 16 may be lifted from the vulcanizer and the pipe structure 25 raised and'turned aside to permit the/removal of the molds in succes j sion from the stack and the mounting of another set of molds on the ram. f

TheV vulcanizing core, 18, referring first to Figs. 1 and 2, is ofthe expansible type, being composed chieiiy of rubber, although I do not wholly limit my claims to an expansible core, and the temperature controlled relief valve y20, positioned diametrically' opposite the inlet tube .19, is mounted upon a metal tube 29 traversing and anchored in the wall of the core and having-a short extension 30'within the core opening adjacent the floor of. the latter, so that water of 'condensation will be driven. out through the relief valve in advance of steam or air.

The mouth of said extension 30 being sub- 3, the inlet tube 19 and the temperature controlledjrelief valve 20 are mounted closely 4 through the inlet tube 19 to flow throughoutl substantially the entire circumferential length of the core, but inone direction only, to the relief valve.

i Iny the modified core of Fig. 4, the inlet tube 19 and relief valve 2O are positioned close to each other; as in Fig. 3, but the partition 31 ofFig, 3 is omitted and the pipe 29 is provided, within the core, with a. long, flexible extension 32, which may be either of metal or other suitable material, said eX- te'nsion reaching to a part of the core substantially opposite the inlet tube 19, so as to provide substantially the sameeifect as to the flow of fluid, as is obtained fin the construction of Fig. 2.

The relief valve 20 of Figs. 1 to 5, shown in detail in Fig. 5, is of a type heretofore know/n, adapted to close in response to the temperature of the fluid passing therethrough, and comprises an outer barrel member 33 connected to the pipe 29 and formed with an L-shapedV fluid passage 34 therethrough, leading from said pipe to a laterally directed dischage orifice 35. Mounted in said passage adjacent the pipe29 is a va'lveseat 36 and adapted to seat thereon is a conical valve head 37 having a stem 38 extend-` ing, with a sliding fit, through .the end-closure member 39a of a cartridge or casing 39,'the latter being supported -in the passage A34 by a head 40 on the casing, said head be- .ing screwed into a bore in the end of the barrel member 33 and backed by a/ closure plug 41 screwed into said bore;

The end, of the .valve stem 38 within the casing 39 ,is secured to an end-closure member 42 of a corrugated metal tube 43 surrounding said stem and having its other end abutting and preferably sealed to the inner face of the end-closure member 39a of the casing 39; The space between said' casing and thev corrugated'tube 43 being filled with oil or other suitable heat-expansible liquid, the valve head 37 is adapted to be forced against its seat 36 by expansion of said fluid,k against the force of the corrugated tube 43, the latter acting as a spring as well as a fiuid retaining wall, and the closure member 42.0f the corrugated tubeacting Somewhat in the manner of a piston, as will be readily understood. 44 is a closure plug for' an observation opening in the wall of the 'barrel member 33', said .opening being adapted to facilitate the accurateA setting of the cartridge to close the valveat a desired temperature. l

The-modified relief valveshown in Fig.. 6 is of similar construction and operation il o ' "neonata except that it is adapted to close in response to the temperature of the medium surround- .ing it instead of that of the vented'Y fluid,

said fluid being vented through apertures 45, 45 leading from the valve seat 46 directly to the exterior of the outer barrel member.

l The latter is cut away about the cartridge, as

below that at which the tires are to be vul# canized, and, the tires being mounted in the apparatus as shown 1n Fig. 1, steam 1s rst let into' the cores 18 through the inlet tubes 19 at a line pressure of about 100 lbs., for example, the steam flowing rapidly through the cores and escaping through the temperature controlled relief valves into the heater chamber, thus driving the air and Water of condensation from the cores. The heater chamber may be vented if desired, although 'I do not exclude the idea of building up a steam pressure in said chamber, during or before this part of the operation, by flovv of steam through the cores or otherwise, such as will not prevent the desired rapid flow ofsteam through the cores for a time sufficient to expel substantially all of the air therefrom.

vThe relief valves having been previously set, as above stated, to close at a determinate temperature, such as 287 F., for example, corresponding to a steam-pressure of about 4,() lbs., the core will have been so heated in a short time, approximating` that required for the expulsion of the air, as to permit steam to pass the valves at such temperature as. to'close thelatter, whereupon the pressurev Wlthin the cores Will quickly build up to the 100 lbs. pressure of the steam line, Without excessive accumulation of Water of condensation inthe cores.

Preferably such steam pressure is then maintained Within the cores for a time sufricient to `further heat and soften the tires, the corresponding temperature being about 338. 'Such preliminary,internallheating of the tires is preferably continued4 for,A about p -20 minutes, during which time a'steamjpressure of about 52 lbs., With a temperatureof about 300 F., is maintained in the heater l chamber. The steam supply is thenshut :oflt'l from the cores and Water. from a line havingy I a temperature of about 300 F., and apressure of about 300 lbs., which is substantially greater than the corresponding steam pressure, is letvinto the cores, condensing thesteam therein and expanding the tires greater than ythe steam pressurecorresponding to its temperature may be initially let into the cores, the Water which first enters the cores flashing into steam and driving the air therefrom. In' the procedure last suggested, of course the extent to which the several advantages of my invention will be obtained will depend upon the position, in

the conduit leading to the cores, at Which.

the lWater is permitted to expand as steam, and upon the rate at which it is permitted to flow past such position. Y

My invention provides for the quick heating of the tires from the interior as Well as through? the molds, so as to obtain a quick and uniform vulcanization, the heat-retarding effect of the air being quickly eliminated by the thorough expulsion of the latter. Oxidation of the interior'vsurface of the core is avoided, quick equalization of temperature throughout the interior of: the core is eil'ected,'and these several advantages are obtained with comparatively little labor and expenditure-of time and care in the matter of closing and opening luid connections. As the relief valves may be set to close very accurately at a determinate temperature, uniformity between successive cures of ti es may be had. Unexpelled Water of conden Aation within the cores is of such small amount as not greatly to coolthe high pressure Water which is let in for the expanding and linal heating of the tires, so that a very close determination of the inal vulcanizing teniperature of the Water'is made possible, *and as the air is very thoroughly expelled the core-may be filled substantially full of water by condensation of the residual steam, the pocketing of residual air` being avoided. v l.

While I have-described the operation more particularly as it relates to cores equipped I with the relief valve of Fig. 5, the operation may be substantially the same With the re- Klief valve@ of Fig. 6, except that when this type of relief valve is used the temperature schedule in the heater chamberl must be so flow of steam inl one direction than in the otherfrom the inlet tube 19, may take place. It will be understood, however, that my invention is not wholly limited to the use of a core as the means for confining the fluid in the space within the hollow article.

Various modifications in additionV to those above described may be resorted towithout departing from the scope of my invention, and l do not wholly limit my claims to the specific forms thereof shown and described.

l cla-im:

'1.7' The method of vulcanizing a hollow rubber article which comprises expelling 'air therefrom by passing anA innocuous fluid therethrough, said fluid being so injected and vented at different points as to be com* lpelled to flow substantially throughout the space within the article, stopping the escape --f of said fluid when a determinate temperature condition is attained, and vulcanizing the article without permitting re-entry of air thereinto. l

.Q /The method yof vulcanizing a hollow rubber article which comprises expelling air therefrom by passing therethrough a heated fluid'` said fluid being so injected and vented at different points as to be compelled to flow substantially throughout* the space within the article, then stopping the escape of said fluid when a determinate temperature condition'is attained, and vulcanizing the article while confining the residual fluid therein.

3. The method of vulcanizi'ng a' .hollow rubber article which comprises expelling air therefrom by passing steam `therethrough from a point of ingress to a point of egress operatively remote therefrom, then stopping the escape of said steam and vulcanizlng' ,the article 'while confining the residual fluid therein.

4. -The method of vulcanizing a hollow rubber article which comprises passing a heated fluid therethrough, then stopping the escape of said fluid when determinate temperature condition is attained-and vulcanizing the article ,while confining the residual fluid therein.

5. The method of vulcanizing a hollow rubber article which comprises expelling air therefrom by passing steam therethrough from a point of ingress to a different point of egress as to expel substantially all air and water of condensation from said article, then stopping the escape'of vsaid steam and vulcanizing the article while holding it eX- panded against a mold by additional fluid forced thereinto.

(3. The method of vulcanizing a hollow rubber article, which comprises passing steam therethrough from a point of ingress toa different point of egress, then stopping the escape of said steam, condensing the' residual7 steam in said article by the force of water thereon at a vulcanizing tempera.- ture and under a; pressure greater than the corresponding' steam pressure, thereby eX- -pandingsaid article against a mold, and

vulcanizing it whileit is so expanded.

v'Z'. The method of vulcanizing a hollow rubber article, which comprises passing` steam therethrough from a point of ingress to a point of egress operatively remote therefrom, then stopping the escape of said steam when the temperature of the escaping steam has reachedla determinate value, and

vulcanizing ,the article while confining the member, stopping the escape of said fluidwhen a determinate temperature condition is attained, and-then vulcanizing the article while 4preventing reentry of air into said member.

9. The method of vulcanizing a rubber article against a hollow, expansible mold member which comprises sopassing a heatedfluid therethrough from a point of ingress to a different point of egress as to compel said fluid to flow substantially throughout the space within said member,

then stopping the escape of said Huid and vulcanizing theN article .while holding said member expanded by confining the residual fluid under pressure therein.

l0. The method of vulcanizing a rubber article against a' hollow, eX'pansible mold member which comprises so passing a' heated fluid therethrough from a point of ingress to a different point of egress as to' compel said fluid tov flow substantially throughout the space within said member,

then stopping the escape of said fluid when a determinate temperature condition is attained and vulcanizing the' article. while holding said member expanded by`con1ining the residual fluid under pressure therein.

1l. The method of vulcanizing a hollow vrubber article on a hollow, expansible core which comprises so passing steam therethrough from a point of ingress to a different point of egress as to compel said steaml v.to flow throughout the space within sald core, then stopping the escape of said steam and condensing the residual steam in said article by the force yof water thereon at a temperature and under a pressure greater than the corresponding steam pressure, thereby expanding the core and article, and vulcanizing the article while it is so eX- panded.

The methodof vulcanizing `a hollow I rubber article ena hollow, expansible coreo whena determinate temperature condition 4 is so expanded.

hollow, expansible molding member having -is attained and condensing the residual steam in said article by the force of water thereon at a temperature and under a pres'- sure greater than the corresponding steam pressure, thereby expanding the core and article', and vulcanizing the article While it o'r vulcanizing a hollow 13. Apparatus rubber article, said apparatus comprising means for conducting a heating iuid 'into-xl `the spacewithin theartic-le, and temper'a ture-controlled confining and venting means adapted to permit said Huid to escape 'from said space until a determinate temperature conditionis reached and then to prevent such escape.

14. Vulcanizing apparatus comprising a hollow molding member having a iuid inlet and a Huid outlet, a normally-open valve disposed in said'outlet, and a temperature responsive device for closing said valve.

15. Vulcanizing apparatus comprising a hollow, expansible molding member having a fluid 'inlet and a fluid outlet, said outlet being operatively remote vfrom said inlet, a normally-open valve disposed in said outlet, and means responsive to thevtemperature of I lthe iiuid passing through said outlet for closing the said valve.

16. Vulcanizing apparatus comprising a a fluid inlet and a fluid outlet,- said outlet being operatively remote from said inlet, a temperature-controlled valvel on said outlet, and a tube extending from said outlet into said member and opening adjacent the floor thereof.

ings, said apparatus comprising means defining an" annular space within the tire casing, means -for circulating a heated Huid therethrough to sweep out the'air confined in said space, and temperature-responsive means for shutting ofi' the said circulation of the heated fluid when the air has been substantially removed from the said space*- ning'an annular space within the tire casing, meansfor circulating steam therethrough y to sweep out the air confined in said" space, 'and automatic means responsive to the temperature of the fluids being ejected from' said's'pace to shut oi the circulation of steam upon said ejected fluids reaching .a predetermined temperature.,

17. Apparatus for vulcanizing tire cas- 4'5.

18 Apparatus for vulcanizing tire cas- Y ings, said apparatus comprising means. de-` 19. Apparatus for vulcanizin tires, said apparatuscomprising an expansi le tire core having a cavity therein in-the form 4of a partial annulus, an inlet adjacent one ex-r tremity o said cavity, an outlet adjacent the other extremity thereof, a normally-open valve disposed in said outlet', and means responsive tothe temperature of uid passing through said outlet for closing said valve.

lIn' witness whereof I have hereunto set my hand this 23rd day' of January, 1924. JOHN R. ,GAM]SIETER. 

